Validation of an analytical method for determination of eight food dyes in beverage and fruit roll-ups by ion-pair HPLC-DAD

Background and aims: Synthetic dyes are widely used as food additives to avoid the loss of original dye in processed foods and to make the foods more attractive to consumers. For simultaneous determination of 8 most commonly used synthetic colors in beverage and foodstuff, an efficient, selective, and sensitive method is suggested. Methods: To analyze food colors in different beverages and fruit roll-ups, a method using Ion-pair high-performance liquid chromatography with diode array detector was suggested and validated. The separation of dyes from beverage and foodstuff was done by solid-phase extraction (SPE). The ultrasound-assisted solvent extraction method was used to extract dye from fruit roll-ups. Results: The limit of detection and the limit of quantification ranged from 0.036 to 0.07 and 0.098 to 0.2 µg/mL, respectively. IP-HPLC-DAD method was validated using precision (RSD %) and accuracy (Recovery %) of two concentrations of 0.5 and 1 µg/mL in terms of intra- and inter-day. SPE method was also validated using intra- and inter-day precision and accuracy. The most commonly detected dye in the tested samples was carmoisine with a concentration of 386 µg/g. Additionally, the concentration of dye was higher than the permitted level in 28.6% of beverages, 40% of edible ice products, and 100% of fruit roll-ups (Lavashak). Conclusion: This method is an effective, appropriate, accessible, reliable and safe analytic method to analyze eight food dyes